The present invention relates in general to farm tractors or the like and, more particularly, relates to farm tractors including a supporting frame assembly on which are mounted an engine, a drive transmission and front and rear wheel axles.
In prior art constructions, the fuel tanks of tractors are generally situated at a rearward end of the tractor or at the side thereof beneath the hood of the engine. In any event, the fuel tanks of prior art tractors are usually separate from the supporting frame assembly of the tractor and not integral therewith.
The assignee of the instant application has manufactured tractors comprising a front frame or cradle constructed of welded beams or of a casting on which the tractor engine is mounted rearwardly of the front wheel axle. A gearbox having a relatively short dimension in the longitudinal direction is situated at a rearward end of this tractor and the fuel tank is situated in the space between the engine and the gearbox in a lower part of the tractor.
A common problem which exists in all conventional tractors is to provide the same with a sufficiently large capacity fuel tank. Thus, the volume of the fuel tank should preferably be sufficiently large to provide the capacity for accommodating fuel requirements for an entire working day. However, in prior art constructions, the fuel tanks of prior art tractors have not had such capacities.
Moreover, the oil sump of a tractor engine in prior art tractors has been constructed either by welding sheet metal or by a low weight casting. It is well known that such an oil sump is generally situated between the side members of an auxiliary frame of the tractor. However, the use of a separate auxiliary frame has directly resulted in an increase in the weight of the tractor and has additionally increased the complexity of the tractor construction. In such prior art tractors, the tractor engine has been situated rearwardly of the front axle which results, especially in the case of tractors having four-wheel drive, in insufficient weight being obtained over the front wheel axle and thereby rendering it necessary to provide additional weights at the front end of the tractor. The auxiliary frame associated with the oil sump has additionally rendered the repair and maintenance operations on the tractor more difficult since the auxiliary frame hinders access to the engine as well as to certain parts of the transmission and thereby makes it difficult to remove such tractor components during repair and maintenance. Moreover, especially in the case of four-wheel drive tractors and additionally with a view towards improving the quality of steering of tractors, it is also important that the tractor weight be distributed such that a relatively great weight is situated over the front wheel axle to provide good traction.
A farm tractor is disclosed in applicant's copending U.S. patent application Ser. No. 460,816 filed Jan. 25, 1983 in which the tractor engine is provided with a self-supporting oil sump which forms a structural component of the supporting frame assembly of the tractor, the wheel axle of the tractor being directly attached in connection with the oil sump. Certain aspects of the present invention are partly related to the invention described in said copending U.S. patent application